Actor Tom Hardy has fuelled speculation he has wed in secret after referring to his fiancee Charlotte Riley as his wife.

The Inception star was promoting his new movie Locke at the Cinema Society in New York City when talk turned to life with his actress girlfriend.

Hardy told reporters, "Well my wife is an actor as well so she sort of gets it..."

When asked what he liked most about brunette Riley, he added, "She's pure. She's just a very kind, pure person."

He went on to refer to himself as a "boyfriend", not a husband, and Hardy wasn't wearing a wedding ring.

The couple has been engaged since 2010.

The actor's publicist has yet to comment on what appears to be a slip of the tongue.